CN102364725A - Method for preparing manganese-based layered crystal structure positive electrode material of lithium battery - Google Patents

Abstract

The invention relates to a technology for manufacturing a positive electrode material of a lithium ion battery, and concretely relates to a method for preparing a manganese-based layered crystal structure positive electrode material of a lithium battery. The method of the invention comprises the following steps: 1, preparing a spherical precursor (NixCoyMnz)(OH)2 (the x:y:z value is 0.133:0.133:0.534); 2, preparing a layered crystal structure Li[Li0.20Ni0.133Co0.133Mn0.534]O2 through a high temperature solid phase process; and 3, coating with Al2O3 to increase performances of Li[Li0.20Ni0.133Co0.133Mn0.534]O2 particle products. The positive electrode material and the preparation method of the invention, which use a cheap metal manganese to replace most cobalt in lithium cobalt oxide, have the advantages of low raw material cost and simple preparation technology, and the powdery micro-particles show excellent battery performances.

Description

The preparation method of lithium battery cathode material with manganese-based layered-crystal structure

Technical field

The present invention relates to the manufacturing technology of anode material for lithium-ion batteries, specifically is a kind of preparation method of lithium battery cathode material with manganese-based layered-crystal structure.

Background technology

Anode material of lithium battery commonly used in the market mainly contains three kinds: cobalt acid lithium (LiCoO ₂), LiMn2O4 (LiMn ₂O ₄) and LiFePO4 (LiFePO ₄).

Cobalt acid lithium (LiCoO ₂) have layered crystal mechanism, the about 140mAh/g of accumulate capacity, cycle performance is more superior, but in the expensive price owing to the raw material cobalt, its application is confined to small-capacity cells, for example the rechargeable battery of small-sized electronic product.

LiMn2O4 (LiMn ₂O ₄), having spinel crystal structure, the cost of raw material is lower, but its capacity has only 100mAh/g, than cobalt acid lithium low about 40%.And its cycle performance is greater than 50 ⁰(Electric power car operating temperature) can weaken greatly under the higher temperature of C, so preferred material that neither following Electric power car.

LiFePO4 (LiFePO ₄), having olivine crystal structure, capacity is about 150mAh/g.Its cost of raw material is lower, but because of its preparation technology is extremely complicated, final finished electrode material price is still than higher.LiFePO4 is because the non-constant of its conductance; The powder particle that need process Nano grade just can show reasonable cycle performance of battery; This is just to causing very big difficulty on the preparation technology; Domestic have some producers attempting production, but because of its batch quality instability, can not go into operation on a large scale always.

Summary of the invention

Technical problem to be solved by this invention provides the preparation method of the lithium battery cathode material with manganese-based layered-crystal structure that a kind of cost of raw material is low, preparation technology is simple, capacity is high.

Method of the present invention is:

Step 1, spherical (Ni _x Co _y Mn _z ) (OH) ₂(x:y:z=0.133:0.133:0.534) preparation of presoma may further comprise the steps:

1) with Ni (CH ₃COO) ₂, Co (CH ₃COO) ₂, Mn (CH ₃COO) ₂, example wiring solution-forming in the distilled water of deionization in molar ratio, cation molar concentration rate Ni:Co:Mn=0.133:0.133:0.534, the concentration summation of final all positive ions is 1.0 mol;

2) the KOH aqueous solution solution with 0.1 mol adds in the blender, and the blender mixing speed is 1000rpm, and temperature is at 20-30 ⁰C;

3) the hybrid metal solution of being joined in the step 1) is splashed in the blender, to produce (Ni _0.166Co _0.166Mn _0.688) (OH) ₂The deposition of particle;

4) after reaction finishes, with (the Ni that precipitates _0.166Co _0.166Mn _0.668) (OH) ₂Granular product filters out and 110 ℃ of dryings, obtains graininess (Ni _0.166Co _0.166Mn _0.668) (OH) ₂Presoma.

Step 2, High temperature solid-state method prepares layered crystal structure Li [Li _0.20 Ni _0.133 Co _0.133 Mn _0.534 ] O ₂ , may further comprise the steps:

1) with graininess (Ni _0.166Co _0.166Mn _0.668) (OH) ₂Presoma is with LiOHH ₂The O powder evenly mixes to get up, and the mixing molar ratio is Li ⁺: metal ion summation=1.3: 0.8;

2). top mixed-powder is placed the sintering furnace of air atmosphere, 480 ℃ of heating 5 hours, be warming up to 950 then earlier ⁰C got final product to such an extent that have [a Li to layered crystal structure Li in air in sintering 10-20 hour _0.20Ni _0.133Co _0.133Mn _0.534] O ₂Granular product;

Step 3 is through Al ₂ O ₃ Coating increases Li [Li _0.20 Ni _0.133 Co _0.133 Mn _0.534 ] O ₂ The performance of granular product may further comprise the steps:

1) with resulting Li [Li _0.20Ni _0.133Co _0.133Mn _0.534] O ₂Granular product places stirred reactor, adds the industrial alcohol of weight concentration 95% ~ 99%, and solid-to-liquid ratio is 3:1 ~ 1:1, stirs the back and adds the aluminium salt sol, and colloidal sol adds speed control at 0.5mL/s ~ 5mL/s; The aluminium salt sol carries out under the condition of toluene hydrotropy with aluminium isopropoxide, and collosol concentration is controlled at 20% ~ 25%;

2) behind the adding colloidal sol, mix and stir 0.5h ~ 2h, slip is transferred in the bipyramid rotary vacuum dryer, vacuumizing and drying, 80 ℃ ~ 90 ℃ of design temperatures, oven dry 2h ~ 4h;

3) with top oven dry material in air 400 ⁰C ~ 600 ⁰C heated 4 h ~ 10 hours, obtained Al ₂O ₃Coat Li [Li _0.20 Ni _0.133 Co _0.133 Mn _0.534 ] O ₂ Granular product, final Al ₂O ₃Quality account for 0.1% ~ 3% of gross product.

Positive electrode of the present invention and preparation method thereof substitutes the most cobalts in the cobalt acid lithium with more cheap manganese metal, and the cost of raw material is lower, and preparation technology is simple, and the powder particle of micron level can show remarkable battery performance.

Embodiment of the invention step is following:

One: spherical (Ni _x Co _y Mn _z ) (OH) ₂(x:y:z=0.133:0.133:0.534) preparation of presoma.

1). with Ni (CH ₃COO) ₂, Co (CH ₃COO) ₂, Mn (CH ₃COO) ₂, example fits over wiring solution-forming in the distilled water of deionization in molar ratio, cation molar concentration rate Ni:Co:Mn=0.133:0.133:0.534, and the concentration summation of final all positive ions is 1.0 mol.

2). KOH is made into the solution of 0.1 mol in distilled water.

3). the KOH aqueous solution solution of getting 10 liters of 0.1 mol that disposed adds in the stirred reactor, and the blender mixing speed is 1000rpm, and temperature is (20-30 at room temperature ⁰C) get final product.

4). with total amount the hybrid metal solution of being joined in 0.48 liter the first step Very slow Splash in the blender, to produce (Ni _0.166Co _0.166Mn _0.688) (OH) ₂The deposition of particle, whole splashing into the about 12-40 of process need hour keeps the high-speed stirred of 1000rpm in the process that splashes into hybrid metal solution

5). after reaction finishes, the total amount that precipitates is about 0.48 mole (Ni _0.166Co _0.166Mn _0.668) (OH) ₂Granular product filters out and 110 ⁰Dry about C.Resulting granules shape (Ni _0.166Co _0.166Mn _0.668) (OH) ₂Presoma.

Two: high temperature solid-state method prepares layered crystal structure Li [Li _0.20 Ni _0.133 Co _0.133 Mn _0.534 ] O ₂

1). with front resulting granules shape (Ni _0.166Co _0.166Mn _0.668) (OH) ₂Presoma is with LiOHH ₂The O powder evenly mixes to get up.Mixing molar ratio does

Li ⁺: metal ion summation ≈ 1.3: 0.8.Attention the ratio here is greater than Li [Li _0.20Ni _0.133Co _0.133Mn _0.534] O ₂In theoretical value (1.2:0.8).We use excessive lithium, because the sub-fraction lithium can vapor away in sintering process.

2). top mixed-powder is placed the sintering furnace of air atmosphere, earlier 480 ⁰C heating 5 hours is warming up to 950 then ⁰C got final product to such an extent that have [a Li to layered crystal structure Li in air in sintering 10-20 hour _0.20Ni _0.133Co _0.133Mn _0.534] O ₂Granular product.

Three: through Al ₂ O ₃ Coating increases Li [Li _0.20 Ni _0.133 Co _0.133 Mn _0.534 ] O ₂ The performance of granular product

1) with the resulting Li [Li in front _0.20Ni _0.133Co _0.133Mn _0.534] O ₂Granular product places stirred reactor, adds 95% ~ 99% industrial alcohol, and the solid-liquid ratio is a standard to form mobile slip, with reference to 3:1 ~ 1:1.Stir after 5 minutes, add the aluminium salt sol.Colloidal sol adds speed control at 0.5mL/s ~ 5mL/s.

2) aluminium salt sol carries out under the condition of toluene hydrotropy with aluminium isopropoxide.Collosol concentration is controlled at 20% ~ 25%.

3) behind the adding colloidal sol, mix and stir 0.5h ~ 2h, slip is transferred in the bipyramid rotary vacuum dryer vacuumizing and drying, design temperature 80 ⁰C ~ 90 ⁰C, oven dry 2h ~ 4h.

4). with top oven dry material in air 400 ⁰C ~ 600 ⁰C heated 4 h ~ 10 hours, can obtain Al ₂O ₃Coat Li [Li _0.20 Ni _0.133 Co _0.133 Mn _0.534 ] O ₂ Granular product.Final Al ₂O ₃Quality account for 0.1% ~ 3% of gross product.

By Al ₂O ₃Coat Li [Li _0.20 Ni _0.133 Co _0.133 Mn _0.534 ] O ₂ Granular product shows higher charging and discharging capacity and cycle life.

Claims (1)

1. the preparation method of a lithium battery cathode material with manganese-based layered-crystal structure is characterized in that:

Step 1, spherical (Ni _x Co _y Mn _z ) (OH) ₂(x:y:z=0.133:0.133:0.534) preparation of presoma may further comprise the steps:

1) with Ni (CH ₃COO) ₂, Co (CH ₃COO) ₂, Mn (CH ₃COO) ₂, example wiring solution-forming in the distilled water of deionization in molar ratio, cation molar concentration rate Ni:Co:Mn=0.133:0.133:0.534, the concentration summation of final all positive ions is 1.0 mol;

2) the KOH aqueous solution solution with 0.1 mol adds in the blender, and the blender mixing speed is 1000rpm, and temperature is at 20-30 ⁰C;

3) the hybrid metal solution of being joined in the step 1) is splashed in the blender, to produce (Ni _0.166Co _0.166Mn _0.688) (OH) ₂The deposition of particle;

4) after reaction finishes, with (the Ni that precipitates _0.166Co _0.166Mn _0.668) (OH) ₂Granular product filters out and 110 ℃ of dryings, obtains graininess (Ni _0.166Co _0.166Mn _0.668) (OH) ₂Presoma;

Step 2, high temperature solid-state method prepare layered crystal structure Li [Li _0.20Ni _0.133Co _0.133Mn _0.534] O ₂, may further comprise the steps:

1) with graininess (Ni _0.166Co _0.166Mn _0.668) (OH) ₂Presoma is with LiOHH ₂The O powder evenly mixes to get up, and the mixing molar ratio is Li ⁺: metal ion summation=1.3: 0.8;

2). top mixed-powder is placed the sintering furnace of air atmosphere, 480 ℃ of heating 5 hours, be warming up to 950 then earlier ⁰C got final product to such an extent that have [a Li to layered crystal structure Li in air in sintering 10-20 hour _0.20Ni _0.133Co _0.133Mn _0.534] O ₂Granular product;

Step 3 is through Al ₂O ₃Coating increases Li [Li _0.20Ni _0.133Co _0.133Mn _0.534] O ₂The performance of granular product may further comprise the steps:

1) with resulting Li [Li _0.20Ni _0.133Co _0.133Mn _0.534] O ₂Granular product places stirred reactor, adds the industrial alcohol of weight concentration 95% ~ 99%, and solid-to-liquid ratio is 3:1 ~ 1:1, stirs the back and adds the aluminium salt sol, and colloidal sol adds speed control at 0.5mL/s ~ 5mL/s; The aluminium salt sol carries out under the condition of toluene hydrotropy with aluminium isopropoxide, and collosol concentration is controlled at 20% ~ 25%;

2) behind the adding colloidal sol, mix and stir 0.5h ~ 2h, slip is transferred in the bipyramid rotary vacuum dryer, vacuumizing and drying, 80 ℃ ~ 90 ℃ of design temperatures, oven dry 2h ~ 4h;

3) with top oven dry material in air 400 ⁰C ~ 600 ⁰C heated 4 h ~ 10 hours, obtained Al ₂O ₃Li [the Li that coats _0.20Ni _0.133Co _0.133Mn _0.534] O ₂Granular product, final Al ₂O ₃Quality account for 0.1% ~ 3% of gross product.